JCombobox connecting to mysql

Hello, I'm new in java.

How I can connect mysql to JCombobox?

I already researched it but I really don't understand.


My JCombobox is inventcateg
my table is category
the column that I need in my JCombobox is categoryNo

here's my code:
I don't know where I will be putting codes to connect my JCombobox to mysql. Please help me.

Code :

---

package aaaaa;
import java.sql.*;
 
public class InventoryS extends javax.swing.JFrame {
 
    private Connection connect;
 
    public InventoryS() {
        initComponents();
 
        try{
            Class.forName("com.mysql.jdbc.Driver");
            connect = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/aaaaa","root","");
            statusTextArea.setText("Connection SUCCESSFUL!");
        }
        catch (Exception f)
        {statusTextArea.setText(f.getMessage());
 
        }
    }
 
 
    @SuppressWarnings("unchecked")
 
 private void formWindowClosing(java.awt.event.WindowEvent evt) {                                   
        try
        {
            connect.close();
        }
        catch(Exception f){};
    }                                  
 
    private void saveButton3ActionPerformed(java.awt.event.ActionEvent evt) {
        String inventcodef = inventCodeField.getText();
        String inventnamef = inventNameField.getText();
	String inventcateg = "Select categoryNo from category order by categoryNo;
        int inventreorderf = Integer.parseInt(inventReorderField.getText());
        String inventlocf = inventLocationField.getText();
        String inventstat = inventStatusArea.getText();
 
        try {
            String SQL2 = "INSERT INTO inventory VALUES ("
                    + "'" + inventcodef + "'" + ","
                    + "'" + inventnamef + "'" + ","
                    + "'" + inventreorderf + "'" + ","
                    + "'" + inventlocf + "'" + ","
                    + "'" + inventstat + "'"
                    + ")";
 
            PreparedStatement stamt = connect.prepareStatement(SQL2);
            stamt.executeUpdate();
 
            statusTextArea.setText("Successfully saved!");
        } catch (Exception f) {
            statusTextArea.setText(f.getMessage());
 
        }
    }
 
 
    public static void main(String args[]) {
 
       java.awt.EventQueue.invokeLater(new Runnable() {
 
            public void run() {
                new InventoryS().setVisible(true);
            }
        });
    }

---

Thanks in advance!

Please use the code tags, and please define what you mean by 'connect them'.

What I mean for "connecting" is retrieving my data from MYSQL and place them into the JCOMBOBOX then whatever the user choose it will be saved :)
Thanks in advance :)